Fix bug in cert_type
This PR fixes a bug in _cert_type that caused it to incorrectly identify EECs as proxy.
Maintenance will be performed on git.ligo.org, containers.ligo.org, and docs.ligo.org on Tuesday 2 July 2024 starting at approximately 9:30am PDT. It is expected to take around two hours and there will be several periods of downtime throughout the maintenance. Please address any comments, concerns, or questions to the helpdesk.
This PR fixes a bug in _cert_type that caused it to incorrectly identify EECs as proxy.